1. Field of the Invention
The present invention relates to devices for manipulating an optical fiber. More particularly, the present invention is directed to a system for storing and dispensing a coaxially housed optical fiber and for securely gripping and longitudinally advancing the fiber when guided through a lumen having a tortuous path.
2. Description of Related Technology
Various technologies require that an optical fiber be kept in a sterile environment from which it may be withdrawn as needed. Some applications require that the optical fiber be stored again after a period of use. Also, there may be some requirement that the fiber be advanced along a path which offers some longitudinal resistance.
Although optical fibers are used in a broad variety of illumination and communication devices, a particular technology that requires all of the characteristics of sterility, reusability, controlled withdrawal of a fiber from a coaxial sheath, and advancement of the fiber along a tortuous path is the field of laser enhanced transluminal angioplasty catheters. Laser enhanced catheter devices are useful for treatment of certain types of obstructions or occlusions formed or created in blood vessels which have plaque build-up or the like, with exposure to laser beam energy being undertaken in order to obtain either a partial removal, reduction and/or the elimination of the obstruction by means of such exposure. An optical fiber member is utilized for transmitting or conducting a beam of laser energy from a generator onto an output lens for delivery of the laser energy onto or against the plaque or other matter obstructing or occluding a blood vessel. Laser enhanced transluminal angioplasty catheter devices are considered valuable tools for the treatment of commonly encountered forms of arteriosclerosis and the like.
In many cases, this procedure is effective in reopening the blood vessel and restoring substantially normal circulation. The procedure is, however, especially dependent upon the skill of the physician, and particularly as that skill pertains to manipulation and ultimate direction and control of the catheter.
Previous devices having broad application to the advancement of wires or extremely slender cylindrical members are disclosed, for example, in U.S. Pat. No. 4,057,186, which discloses a wiring pen for use in advancing a relatively rigid copper wire. Such a device is unsuitable for use with an optical fiber due to the extreme flexibility and poor longitudinal compressive resistance of the optical fiber member.
A system designed to manipulate an optical fiber in the context of laser enhanced transluminal angioplasty catheters is disclosed, for example, in U.S. Pat. No. 4,669,465, which includes a hand-held fiber advance unit which controls the insertion or extent of advance of the lasing fiber relative to the distal tip of the catheter. This particular device suffers from mechanical complexity and a lack of tactile feedback to the operator who is necessarily required to make extremely subtle adjustments regarding the absolute position of the optical fiber.